The choice that provides the most effective transition from the preceding sentence to the one that follows is B. Turning our attention to a different topic, consider the characteristics of marriage among the aristocracy and commoners as detailed in chapters 6 and 7.
This option explicitly signals a shift in focus, which is essential for effective transitions in writing. It acknowledges that the discussion is moving to a different topic while also providing a clear preview of what that new topic is - the characteristics of marriage among different social classes.
This helps readers understand the upcoming content and prepares them for the shift in subject matter.
The phrase "Turning our attention to a different topic" is straightforward and leaves no room for ambiguity. It clearly indicates a change in direction and ensures that readers are not caught off guard by the shift.